1. Technical Field
The present invention relates to a physical quantity sensor, a pressure sensor, an altimeter, an electronic apparatus, and a moving object.
2. Related Art
A pressure sensor that includes a diaphragm which is flexurally deformed when receiving pressure is widely used. In such a pressure sensor, a sensor element such as a piezoresistive element or a vibration element is disposed on the diaphragm, then the sensor element detects the flexure of the diaphragm, and thus it is possible to detect pressure applied to the diaphragm.
For example, in a pressure sensor disclosed in JP-A-8-97439, a piezoresistive element and an integrated circuit (IC) that includes a circuit for drive, detection, or the like of the piezoresistive element are provided on one surface of a silicon substrate on which a diaphragm is formed, and a cavity is provided on the other surface of the silicon substrate. The cavity is sealed, and thereby it is possible to realize an absolute-pressure sensor.
However, in the pressure sensor disclosed in JP-A-8-97439, since the cavity is provided on a side opposite to the integrated circuit of the silicon substrate, a problem arises in that the size of the silicon substrate becomes great in the thickness direction. In addition, in the pressure sensor disclosed in JP-A-8-97439, in a case where the sealed cavity is formed, a process has to be included, in which another substrate is bonded to the silicon substrate. Therefore, a problem arises in that cost has to be increased.